RK3588 Linux系统GPIO口测试方法及自动化测试脚本
1、GPIO编号计算... 2
2、测试举例... 2
2.1 gpio_request申请导出相应的gpio. 2
2.2 gpio_direction_output 设置相应gpio为输出方向... 3
2.3 gpio_set_value 设置输出电平... 3
设置输出为高电平... 3
设置输出为低电平... 3
2.4 gpio_get_value 获取gpio当前状态值... 3
2.5 gpio_free 释放申请的gpio. 3
3测试脚本（模拟跑马灯）... 3
1、GPIO编号计算
GPIO pin脚计算公式：pin = bank * 32 + number
GPIO 小组编号计算公式：number = group * 8 + X
例如: gpio4 A0 gpio编号4*32+0*8 +0=128
GPIO(A-0,B-1,C-2...)
gpio4 A0 gpio编号4*32+0*8 +0=128
gpio4 A1 gpio编号4*32+0*8 +1= 129
gpio4 A2 gpio编号4*32+0*8 +2=130
gpio4 C1 gpio编号4*32+2*8 +1=145
在特定的GPIO目录下，会有两个文件:direction和value。如您所料，从它们中读取将返回当前状态(方向/值)。向它们写入将设置当前状态。
可能的指示命令:
high | 设置GPIO为一个起始值为1的输出 |
low | 设置GPIO为起始值为0的输出 |
out | Same as low |
in | 将GPIQ设置为一个输入 |
value字段只是使用数值，所以是0或1。
2、测试举例
gpio4 A0 测试步骤如下：
2.1 gpio_request申请导出相应的gpio
echo 128 > /sys/class/gpio/export
2.2 gpio_direction_output设置相应gpio为输出方向
echo out > /sys/class/gpio/gpio128/direction
2.3 gpio_set_value设置输出电平
设置输出为高电平
echo 1 > /sys/class/gpio/gpio128/value
设置输出为低电平
echo 0 > /sys/class/gpio/gpio128/value
设置后可根据设置电平使用万用表测量对应管脚电压值
2.4 gpio_get_value获取gpio当前状态值
cat /sys/class/gpio/gpio128/value
2.5 gpio_free释放申请的gpio
echo 128 > /sys/class/gpio/unexport
3测试脚本（模拟跑马灯）
echo 145 > /sys/class/gpio/export
echo 120 > /sys/class/gpio/export
echo 121 > /sys/class/gpio/export
echo 155 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio145/direction
echo out > /sys/class/gpio/gpio120/direction
echo in > /sys/class/gpio/gpio121/direction
echo in > /sys/class/gpio/gpio155/direction
cat /sys/class/gpio/gpio121/value
cat /sys/class/gpio/gpio155/value
echo 1 > /sys/class/gpio/gpio145/value
echo 1 > /sys/class/gpio/gpio120/value
cat /sys/class/gpio/gpio121/value
cat /sys/class/gpio/gpio155/value
echo 0 > /sys/class/gpio/gpio145/value
echo 0 > /sys/class/gpio/gpio120/value
cat /sys/class/gpio/gpio121/value
cat /sys/class/gpio/gpio155/value
echo out > /sys/class/gpio/gpio121/direction
echo out > /sys/class/gpio/gpio155/direction
echo in > /sys/class/gpio/gpio145/direction
echo in > /sys/class/gpio/gpio120/direction
cat /sys/class/gpio/gpio145/value
cat /sys/class/gpio/gpio120/value
echo 1 > /sys/class/gpio/gpio121/value
echo 1 > /sys/class/gpio/gpio155/value
cat /sys/class/gpio/gpio145/value
cat /sys/class/gpio/gpio120/value
echo 0 > /sys/class/gpio/gpio121/value
echo 0 > /sys/class/gpio/gpio155/value
cat /sys/class/gpio/gpio145/value
cat /sys/class/gpio/gpio120/value